The present invention relates to a safety workbench having a front pane which has at least one additional cleaning position.
Safety workbenches fulfill various functions. They are generally used for protecting the products to be manufactured or processed within the workbench, the operator, and/or the environment.
The basic construction of safety workbenches comprises an inner chamber enclosed by a housing and a work opening on the housing front side, which is closable using an adjustable front pane. The inner chamber is also identified in the meaning of the present invention as a working chamber or working inner chamber. Such safety workbenches are already known in greatly varying embodiments from the prior art, for example, from DE 44 41 784 A1, DE 102 17 903 C1, DE 297 23 636, and DE 100 17 196 A1.
The front pane plays a central role in the various protective functions of the safety workbench. It largely closes the working chamber in the working position to the external surroundings and prevent the escape of particles, is used, inter alia, as a spray guard for the operator, and, vice versa, also prevents the penetration of particles from the external surroundings into the working inner chamber.
The front pane may essentially assume three different positions in a safety workbench, namely the open final position, in which the front pane and thus also the work are maximally open, the work position, in which the front pane partially covers the work opening in the top area, and the closed final position, in which the front pane essentially completely closes the work opening.
Safety workbenches in laboratories, in particular those which are suitable for microbiological work, must meet strict safety requirements. They have additional fans and/or exhaust devices, which exhaust air contaminated by particles or aerosols through directed airflows, for example, and thus additionally protect the operators. Such a safety workbench is described, for example, in DE 10 2004 032 454 A1. To ensure safe operation, the front pane may not remain too far open over a long time in such a safety workbench, because the required airflows may not be maintained in the event of too large an opening cross-section of the work opening and thus product and personal protection are not ensured.
In addition, an operator is to be able to see into the working chamber through the front pane of the safety workbench and observe the procedures inside the working chamber. A visual check of the working chamber is thus possible.
For various reasons, it may be necessary to clean the entire working chamber of a safety workbench and thus particularly also the interior of the front pane. On one hand, the particular required cleanness of the entire working inner chamber may also be produced and ensured in this way, for example, also by disinfection. On the other hand, the view and thus the visual check of the procedures within the working chamber may be obstructed by direct contamination and dirtying of the front pane. Contaminants must accordingly be removed.
In the known safety workbenches, the front pane is mounted in such a way that it may be pushed up and down essentially parallel to the housing front side. It is not possible here to clean the complete interior of the front pane. The area which may just not be reached during cleaning is additionally in the normal viewing area of operators, so that the visual check is obstructed.
Other front panes of the prior art have additional hinges or other folding mechanisms. The front pane may be opened upward and cleaned on its interior here. During this procedure, the work opening of the safety workbench is completely open to the surroundings. The surroundings are subjected to possible contamination. In addition, the operator is subjected to the possibly contaminated working inner chamber, because he must inevitably approach closely thereto during the cleaning procedure. It is especially disadvantageous that he nearly automatically has to stand below the front pane to be cleaned in this case.
The safety functions of the front pane are thus disengaged in this open position. The contaminated front pane itself even represents an additional risk.
The front panes of the prior art have the additional disadvantage that the cleaning may only be performed from below the opening of the pane and thus the operator is subject to the danger of being contaminated himself by falling dirt or dripping cleaning liquid. This is an especially grave safety risk if an overhead working position results for the operator during cleaning.
The object of the present invention is therefore to provide a safety workbench having a front pane which overcomes the disadvantages of the prior art and in which the front pane is easier to clean completely, without having to completely expose the working chamber.
This object is achieved by the safety workbench having a working chamber enclosed by a housing and a housing front side, which has a work opening, which is closable by an adjustable front pane, wherein the front pane has at least one additional cleaning position, in which it is situated at least partially below a closed final position, in which the work opening is completely covered, in such a way that a cleaning opening is formed between pane top edge and housing.